Star Wars Nite - What to expect?

Since the tickets went on sale today, and my wife and I were lucky to get some, and this will be our first time, I'm wondering what to expect? I think there are lightsaber meetups? Are the costume rules looser on these nights? How hard is it to get the character meet and greets, and the special items/food? Is there exclusive merch? Anything I'm not thinking of? I'd love to hear from those who've gone!